I voted other. It was designed for game balance, but a concept of balance different than what is now termed as game balance.
joe b.
I voted yes, but otherwise agree with the above.
For whatever reason the hobby began to think of its' games as simulation games. Which isn't what roleplaying games are. In a simulation game balance is predetermined by the designer. Balance is achieved by pitting every player against the same challenges each with a pre-set difficulty to overcome. Like in computer games, RPG simulation games saw game balance as a level of difficulty predetermined by the designers. However, sometimes players are given the option to change this beforehand (easy, standard, hard, InSaNe!). In 3e and 4e this was/is set by the DM. If you beat a kobold while playing solo on a bought encounter map in either game, you faced the same difficulty as anyone else playing did in the exact same situation.
Early D&D did not require consistent challenges across games, but only within them. This was an asset in regards to their flexibility. AD&D was actually created to set a predetermined consistency of challenges and their difficulty across all games. As I understand it, this was originally done so convention tournament participants could all be working within the same skill set. That and the game was becoming so varied in its play that modules and other salable items were not applicable to many people's games. Now, in AD&D, each could recognize a monster for what it was from another game and all have an equal chance of beating it. But, ironically, this attempt at formalizing the game backfired and led to the simulation game mindset we've seen for a long, long time now.
It should be said though, neither is AD&D a storygame. Its' ideas of balance had more to do with equivalent rules for individual elements (like monsters, treasure, magic items, combat actions) across all games than in balancing the game according to what degree each player could contribute to a story-making session. It was (and is) still a strategy game where creating a story was not the objective, so giving every player equal story rights did not go into balancing its' design. Each player at the table does play turn by turn (or round by round depending on the situation), but a player's potential influence over what can happen in each turn is radically different for every PC.
AD&D1e and other early editions are balanced according to single players facing the game alone. Each and every game was a solo game against the impartial DM/Ref where additional players enabled the choice of whether or not to assist each other. Every player is rewarded separately and each are in a different situation than each other (regardless of what is going on). What makes the game balanced is every player is attempting to guess the same hidden ruleset behind the screen even though each player may need to achieve different ends within it to gain points. If they were the same Class (role), then the rewarded ends would be the same. But class levels between players, treasure distribution, influence of powers between PCs, the number and influence of allies between PCs, et cetera all have no bearing on the balancing of the game.